package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    @Autowired
    private StringRedisTemplate redisTemplate;
    @Autowired
    private IUserService userService;
    /**
     * 关注和取关
     *
     * @param id
     * @param isFollow
     * @return
     */
    @Override
    public Result follow(Long id, Boolean isFollow) {

        //获取当前登录用户
        Long userId = UserHolder.getUser().getId();
        //判断到底是关注还是取关
        String key = "follows:" + userId;
        if (isFollow) {
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(id);
            boolean isSuccess = save(follow);
            if (isSuccess) {
                //把关注用户的id放入redis的set
                redisTemplate.opsForSet().add(key, id.toString());

            }
        } else {
            remove(Wrappers.<Follow>lambdaQuery().eq(Follow::getUserId, userId).eq(Follow::getFollowUserId, id));
            redisTemplate.opsForSet().remove(key, id.toString());

        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long id) {
        Long userId = UserHolder.getUser().getId();
        //查询用户是否关注
        Integer count = query().eq("user_id", userId).eq("follow_user_id", id).count();

        return Result.ok(count>0);
    }

    /**
     * 求共同关注,两个set求交集
     * @param id
     * @return
     */
    @Override
    public Result followCommons(Long id) {
        //获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key = "follows:" + userId;
        String key2 = "follows:" + id;
        Set<String> intersect = redisTemplate.opsForSet().intersect(key2, key);
        if (intersect==null||intersect.isEmpty()){
            return Result.ok(Collections.emptyList());
        }

        List<Long> collect = intersect.stream().map(x -> Long.valueOf(x)).collect(Collectors.toList());
        List<UserDTO> list = userService.listByIds(collect)
                .stream().map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());

        return Result.ok(list);
    }
}
